Possibilities for developing rationalization potential are to be found in the ever current issue of “set-up times” and in modern production methods such as hard machining and dry machining, in addition to versatile utilization of the machine park. At HAINBUCH, this potential has been recognized, resulting in the departure from “single” clamping devices in favor of a user friendly modular set-up system that enables fast and accurate change-overs with minimum time and expense. The high-precision CENTREX centering system makes use of unique technology that enables the user to change a standard SPANNTOP O.D. clamping fixture in less than two minutes to a full-fledged solid mandrel system for I.D. clamping, or even to a 3-jaw O.D. clamping fixture. This CENTREX interface can be used to advantage not only with standard clamping fixtures, but also with clamping devices for batch production of brake disks, for example. In this application, the change-over of entire chucks is performed while retaining process reliability and without alignment. The CENTREX interface performs the centering function, with centering accuracy of less then 3 µm. The innovation is therefore not only in the individual clamping devices themselves, but also in the modular principle, which due to its diversity of applications drastically minimizes set-up times and interruptions in production. The B-Top3 system was specially developed to enable this modular system to be used for smaller quantities and material dimensions up to a diameter of 210 mm. The jaw chuck used as a basis can be changed quickly and easily to an I.D. clamping device with a solid mandrel or to a circumferential O.D. clamping device. This is especially advantageous, since a jaw chuck – due to its exposed jaws at increased RPMs – tends to quickly lose clamping force. However, it is frequently the deformation of the work piece caused by the narrow jaws that necessitates the use of a circumferential high-precision SPANNTOP clamping device. The user also benefits from the quick change of the end-stop and of the clamping head, which due to its concentric precision of less than 10 µm eliminates the boring of soft jaws on the jaw chuck.
Combined jaw chuck and standard mandrel
The combination of jaw chuck and standard mandrel in the MANDO Adapt 215 enables maximum machining performance with a high degree of concentric precision also with smaller I.D. clamping. The decisive feature here is the circumferential contact between the segmented clamping bushing and the work piece bore. Whether for I.D. or O.D. clamping, chuck elements or bar work, the axial draw force of the mounted adapter clamping device is often what is required for rigid and solid clamping with optimum properties such as high stiffness, vibration reduction and maximum metal removal rates. The modular principle is also what led to the development of a new generation of clamping devices. SPANNTOP Nova, the newest member of the clamp family, sets standards not only in terms of stiffness, precision and service life. It also features – for the first time – the capability of changing over to the new TOPlus technology with a hexagonal clamping principle, by simply replacing a single component.
Full-surface contact even with large tolerances
With the chuck clamping head solutions used in the past, the clamping head fits ideally in the chuck taper only when exactly in clamping position. The work piece tolerances during machining cause radial displacement between the clamping head and the chuck taper. This results in narrow gaps that can be penetrated by contamination, such as fine chips or dust. The performance of TOPlus is convincing with its maximum contact between the clamping element and the truncated pyramid of the chuck. Full-surface contact is ensured even with large work piece tolerances, so that contamination has no chance of penetrating the chuck. A further innovation can be found in the chuck itself, where the exclusive use of steel for clamping devices was put into question. For the first time, a cast mineral composite was used for these chucks, with a similar composition to that already successfully used by mechanical engineers. The use of cast mineral composite makes it possible to inexpensively manufacture the technically difficult-to-produce form of the truncated pyramid for a standard clamping device. Compared with purely steel chucks, this new clamping device is lighter and also has a lower mass inertia torque, which is advantageous especially during high acceleration. Not to mention the positive dampening properties of the cast mineral composite. For the user, this means measurable savings due to increased tool life for cutting tools such as hard metal. In addition, TOPlus achieves a 25% increase in holding power as compared with the standard SPANNTOP chucks, in addition to a considerably longer tool life. This is due to the full-surface contact of the clamping head in the truncated pyramid of the chuck. Steel pads embedded in the cast mineral composite can be lubricated, with the option “Lubrication grooves”, by means of a single lubrication point in order to minimize friction. Due to all of these special features, HAINBUCH is confident: TOPlus is a clamping device with a guaranteed future.
CONCLUSION
- Modular clamping devices have a self-centering interface.
- In less than two minutes a clamping device for I.D. clamping can be changed over to a 3-jaw chuck.
- Chucks with clamping elements made of cast mineral composite provide for high dampening power.
